823 research outputs found

    Symbolic Computation of Variational Symmetries in Optimal Control

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    We use a computer algebra system to compute, in an efficient way, optimal control variational symmetries up to a gauge term. The symmetries are then used to obtain families of Noether's first integrals, possibly in the presence of nonconservative external forces. As an application, we obtain eight independent first integrals for the sub-Riemannian nilpotent problem (2,3,5,8).Comment: Presented at the 4th Junior European Meeting on "Control and Optimization", Bialystok Technical University, Bialystok, Poland, 11-14 September 2005. Accepted (24-Feb-2006) to Control & Cybernetic

    The complete mitochondrial genome of the endemic Iberian pygmy skate Neoraja iberica Stehmann, Séret, Costa, & Baro 2008 (Elasmobranchii, Rajidae)

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    Skates, Chondrichthyes fishes from order Rajiformes, are the most species-rich group of all Batoidea. However, their phylogenetic relationships and systematics is still a highly discussed and controversial subject. The use of complete mitogenome has shown to be a promising tool to fill this gap of knowledge. Here, the complete mitogenome of the Iberian pygmy skate Neoraja iberica (Stehmann, Séret, Costa & Baro 2008) was sequenced and assembled. The mitogenome is 16,723 bp long and its gene content (i.e. 13 protein-coding genes, 22 transfer RNA, and 2 ribosomal RNA genes) and arrangement are the expected for Batoidea. Phylogenetic reconstructions, including 89 Rajiformes and two outgroup Rhinopristiformes, recovered family Rajidae as monophyletic, and further divided in the monophyletic tribe Rajini, sister to tribes Amblyrajini and Rostrorajini. The newly sequenced N. iberica mitogenome is the first representative of the tribe Rostrorajini.FCT: PTDC/ART-DAQ/29537/2017/ FEDER: POCI-01-0145-FEDER-029537/ PT2020 COMPETE 2020 – FCT: UIDB/04423/2020, UIDP/04423/2020 / SFRH/BD/137935/2018/ SFRH/BD/147493/2019 PTDC/ASP-PES/28053/2017info:eu-repo/semantics/publishedVersio

    The gill transcriptome of threatened European freshwater mussels

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    Genomic tools applied to non-model organisms are critical to design successful conservation strategies of particularly threatened groups. Freshwater mussels of the Unionida order are among the most vulnerable taxa and yet almost no genetic resources are available. Here, we present the gill transcriptomes of five European freshwater mussels with high conservation concern: Margaritifera margaritifera, Unio crassus, Unio pictorum, Unio mancus and Unio delphinus. The final assemblies, with N50 values ranging from 1069–1895 bp and total BUSCO scores above 90% (Eukaryote and Metazoan databases), were structurally and functionally annotated, and made available. The transcriptomes here produced represent a valuable resource for future studies on these species’ biology and ultimately guide their conservation.AGS was funded by the Portuguese Foundation for Science and Technology (FCT) under the grant SFRH/ BD/137935/2018, that also supported MLL (2020.03608.CEECIND) and EF (CEECIND/00627/2017). This research was developed under the project EdgeOmics - Freshwater Bivalves at the edge: Adaptation genomics under climate-change scenarios (PTDC/CTA-AMB/3065/2020) funded by FCT through national funds. Additional strategic funding was provided by FCT UIDB/04423/2020 and UIDP/04423/2020.info:eu-repo/semantics/publishedVersio

    “If You Let Them, They Will Be on It 24 Hours a Day”: Qualitative Study Conducted in the United States Exploring Brazilian Immigrant Mothers’ Beliefs, Attitudes, and Practices Related to Screen Time Behaviors of Their Preschool-Age Children

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    Background: The increasing prevalence of excessive screen time (ST) among children is a growing public health concern, with evidence linking it to an increased risk of overweight and obesity among children. Objective: This study aimed to explore the beliefs, attitudes, and practices of Brazilian immigrant mothers living in the United States related to their preschool-age children’s ST behaviors. Methods: A qualitative study comprising 7 focus group discussions (FGDs) was conducted with Brazilian immigrant mothers living in the United States. All FGDs were audio-recorded and professionally transcribed verbatim. The Portuguese transcripts were analyzed using thematic analysis. Results: In total, 37 women participated in the FGDs. Analyses revealed that although most mothers expressed concerns for their preschool-age children’s ST, nearly all viewed ST as an acceptable part of their children’s daily lives. Furthermore, mothers perceived that ST has more benefits than disadvantages. The mothers’ positive beliefs about (eg, educational purposes and entertainment) and perceived functional benefits of ST (eg, ability to keep children occupied so tasks can be completed and facilitation of communication with family outside the United States) contributed to their acceptance of ST for their preschool-age children. Nevertheless, most mothers spoke of needing to balance their preschool-age children’s ST with other activities. Mothers reported using several parenting practices including monitoring time and content, setting limits and having rules, and prompting their children to participate in other activities to manage their preschool-age children’s ST. Conclusions: This study provides new information on the beliefs, attitudes, and practices of Brazilian immigrant mothers living in the United States related to their preschool-age children’s ST. Study findings revealed several potentially modifiable maternal beliefs and parenting practices that may provide important targets for parenting- and family-based interventions aimed at limiting preschool-age children’s ST

    A resource for sustainable management:<i>De novo</i> assembly and annotation of the liver transcriptome of the Atlantic chub mackerel, <i>Scomber colias</i>

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    Mackerels represent a valuable fishery worldwide. Their ample geographic distribution and capture levels make them an insightful model to address stock management strategies in the context of global changes. Yet, and despite recent impressive genome and transcriptome sequencing efforts from teleost species, available resources from the Scombridae family are comparatively scarce. Here, we generated the first high-quality de novo assembly of the liver transcriptome of the Atlantic chub mackerel (Scomber colias). Through the use of RNA-Seq Illumina technology, 111,124,228 clean reads were obtained for the liver transcriptome. De novo assembly resulted in 93,731 transcripts with an N50 of 1462 bp. This dataset provides an important insight into the context of fisheries management. Keywords: RNA-Seq, Scombridae, Stock management, Atlantic chub mackerel, Live

    The cross between valuing fish andsustainability of resources

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    As members of the Animal Science and Technology group (FST), our area of intervention are: on diadromous species (migratory) in the 7 Portuguese river basins; on a very relevant exotic species in main reservoirs in Alentejo (largemouth bass) and on experimental diets for breeding of wild trout in Campelo Aquaculture Station. Diadromous fish are those that migrate between freshwater and saltwater. Only 1% of the known fish species are included in this group, but many of those are that we appreciate gastronomically. We are talking about sea lamprey, shad, sturgeon, European eel, among others. Our team has been developing a partnership with fishermen so that the biological resource is valued, through an analysis of its nutritional, sensory and safety characteristics

    Mitos e Verdades do Pescado na Dieta Mediterrânea

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    Mitos e verdades sobre o pescado na dieta mediterrânica: abordagem desde o tipo de gordura, à caracterização dos produtos aquícolas versus pescado selvagem, aos efeitos das alterações climáticas no pescado e à estreita relação entre os POPs e o pescado

    The crown pearl V2: an improved genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758)

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    Contiguous assemblies are fundamental to deciphering the composition of extant genomes. In molluscs, this is considerably challenging owing to the large size of their genomes, heterozygosity, and widespread repetitive content. Consequently, long-read sequencing technologies are fundamental for high contiguity and quality. The first genome assembly of Margaritifera margaritifera (Linnaeus, 1758) (Mollusca: Bivalvia: Unionida), a culturally relevant, widespread, and highly threatened species of freshwater mussels, was recently generated. However, the resulting genome is highly fragmented since the assembly relied on short-read approaches. Here, an improved reference genome assembly was generated using a combination of PacBio CLR long reads and Illumina paired-end short reads. This genome assembly is 2.4 Gb long, organized into 1,700 scaffolds with a contig N50 length of 3.4 Mbp. The ab initio gene prediction resulted in 48,314 protein-coding genes. Our new assembly is a substantial improvement and an essential resource for studying this species’ unique biological and evolutionary features, helping promote its conservation.AGS was funded by the Portuguese Foundation for Science and Technology (FCT) under the grant SFRH/BD/137935/2018 and COVID/DB/152933/2022, which also supported MLL (2020.03608.CEECIND) and EF (CEECINST/00027/2021). This research was developed under the project EdgeOmics - Freshwater Bivalves at the Edge: Adaptation genomics under climate-change scenarios (PTDC/CTA-AMB/3065/2020) funded by FCT through national funds. Additional strategic funding was provided by FCT UIDB/04423/2020 and UIDP/04423/2020.info:eu-repo/semantics/publishedVersio

    Development of bio-hybrid piezoresistive nanocomposites using silk-elastin protein copolymers

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    Recombinant silk-elastin-like protein (SELP)/carbon nanotubes (CNTs) nanocomposite films with different amounts of CNTs (1, 3 and 6wt%) were prepared by solvent casting. The produced films were stabilized by exposure to methanol that induces an increase of the -structure content. The CNTs were homogeneously distributed into the SELP matrix and did not induce significant alterations into its chemical structure. The incorporation of CNTs also increased the thermal stability of the films. Further, the incorporation of 1wt% of CNTs greatly improved the mechanical properties of the SELP matrix leading to a 6-fold increase in strain-to-failure and to increase the ultimate tensile strength with minor differences in modulus of elasticity. The nanocomposites exhibited a good linearity between deformation and electrical resistance variation with electrical conductivity increasing with the nanofiller content up to 0.8Sm1. Finally, the produced nanocomposites were non-cytotoxic indicating their suitability for biomedical applications.This work was supported by national funds through FCT I.P. (Fundação para a Ciência e Tecnologia, Portugal) and by the European Regional Development Fund (ERDF) through COMPETE2020 Programa Operacional Competitividade e Internacionalização (POCI, Portugal) in the framework of the Strategic Programs UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) and UID/FIS/04650/2013. This work was also supported by the strategic programme UID/BIA/04050/2019 funded by national funds through FCT I.P. The present work was also supported by FCT I.P. within the ERA-NET IB-2 project FunBioPlas (ERA-IB-2-6/0004/2014), EuroNanoMed 2016 call and project LungChek ENMed/0049/2016. DMC, SR and CR also thank FCT I.P. for the grants SFRH/BPD/121526/2016, SFRH/BD/111478/2015, and SFRH/BPD/90870/2012, respectively. This article is a result of the project EcoAgriFood [NORTE-01-0145-FEDER-000009], supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Finally, the authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs.info:eu-repo/semantics/publishedVersio

    Morphological characterization of a human glioma cell l ine

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    A human malignant continuous cell line, named NG97, was recently established in our laboratory. This cell line has been serially subcultured over 100 times in standard culture media presenting no sign of cell senescence. The NG97 cell line has a doubling time of about 24 h. Immunocytochemical analysis of glial markers demonstrated that cells are positive for glial fibrillary acidic protein (GFAP) and S-100 protein, and negative for vimentin. Under phase-contrast microscope, cultures of NG97 showed cells with variable morphological features, such as small rounded cells, fusiform cells (fibroblastic-like cells), and dendritic-like cells. However, at confluence just small rounded and fusiform cells can be observed. At scanning electron microscopy (SEM) small rounded cells showed heterogeneous microextentions, including blebs and filopodia. Dendritic-like cells were flat and presented extensive prolongations, making several contacts with small rounded cells, while fusiform cells presented their surfaces dominated by microvilli. We believe that the knowledge about NG97 cell line may be useful for a deeper understanding of biological and immunological characteristics of gliomas
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